Free Online Physics Calculators

Acoustics & Waves Calculators cover sound propagation and wave behavior. Calculate the speed of sound in air or solids, or use the Doppler effect calculator and beat frequency calculator for moving sound sources and interfering frequencies. The standing wave calculator and wave speed calculator cover general wave mechanics, while dB calculator and dB gain calculator handle sound level measurements.

This section also includes a reverberation time calculator and sound absorption coefficient calculator for room acoustics, plus a Helmholtz resonator calculator, acoustic impedance calculator, interference pattern calculator, and Alfvén velocity calculator for plasma wave physics.

Astronomy Calculators cover orbital mechanics and space travel math. Calculate orbital period and orbital velocity using Kepler's third law, or work out escape velocity and a Hohmann transfer for spacecraft trajectory planning. The rocket equation calculator and rocket thrust calculator size propulsion systems, while delta V and specific impulse calculators quantify fuel efficiency for space missions.

This section also includes a synodic period calculator, Earth orbit calculator, satellite velocity calculator, thrust to weight ratio calculator, and space travel calculator, plus fun tools like the alien civilization calculator and UFO travel calculator for exploring speculative space scenarios.

Astrophysics Calculators cover the physics of stars, black holes, and the universe at large. Calculate the Schwarzschild radius of a black hole or estimate black hole temperature and black hole collision energy, or use Hubble's law calculator and the universe expansion calculator to explore cosmic expansion. The redshift calculator and parallax calculator measure how far away and how fast distant objects are moving.

This section also includes a luminosity calculator, stellar magnitude calculator, light year calculator, gravitational lensing calculator, Olber's paradox calculator, exoplanet discovery calculator, and the Drake equation calculator for estimating the number of civilizations in the galaxy.

Atmospheric & Geophysics Calculators cover weather physics and Earth science measurements. Calculate dew point, relative humidity, and absolute humidity, or estimate wind chill and heat index for how weather actually feels. The air density calculator, density altitude calculator, and atmospheric pressure at altitude calculator account for how air properties change with elevation, while the adiabatic lapse rate and temperature at altitude calculators model temperature change with height.

This section also includes a Richter scale calculator and seismic wave velocity calculator for earthquake measurement, plus a cloud base calculator and wet bulb temperature calculator for aviation and meteorology.

Dynamics Calculators cover forces, motion, and collisions in classical mechanics. Apply Newton's second law to calculate force, or use the momentum calculator and impulse and momentum calculator for collision problems. Elastic collision and inelastic collision calculators model how objects interact on impact, while conservation of momentum calculator and reduced mass calculator support two-body systems.

This section also includes friction, coefficient of friction, normal force, and inclined plane calculators for surface interactions, plus Hooke's law, tension, weight, net force, and an Atwood machine calculator for classic mechanics problems, and a car crash calculator and ballistic pendulum calculator for impact and projectile scenarios.

Electrical Circuits & Electronics Calculators cover circuit analysis from basic Ohm's law to RF design. Apply Ohm's law to calculate voltage, current, or resistance, or use the voltage divider and current divider calculators for multi-component circuits. Resistor, capacitor, and inductor combinations are covered by series and parallel resistor, capacitor, and inductor calculators, while RC circuit, RLC circuit, and resonant frequency (LC) calculators analyze frequency-dependent behavior.

This section also covers wire and power sizing — wire gauge, wire size, wire resistance, and breaker size calculators — plus RF and signal tools like impedance matching, VSWR, free space path loss, and Fresnel zone calculators, and specialized components like the 555 timer, op-amp, Wheatstone bridge, transformer sizing, and three phase calculators for a complete electronics toolkit.

Energy, Work & Power Calculators cover the fundamental quantities that describe how work gets done. Calculate kinetic energy, potential energy, or gravitational potential energy, or use the work calculator and power calculator (mechanical) for basic mechanics problems. The E = mc² calculator and relativistic kinetic energy calculator extend energy concepts to relativistic speeds, while efficiency and power-to-weight ratio calculators compare energy conversion performance.

This section also includes bullet energy, recoil energy, impact energy, and TNT equivalent calculators for ballistics and impact scenarios, plus watt, watt-hour, and electrical power calculators, and a signal-to-noise ratio calculator and EIRP calculator for RF power analysis.

Fluid Mechanics Calculators cover how liquids and gases behave in motion and at rest. Calculate Reynolds number and Mach number to characterize flow regime, or use Bernoulli's equation calculator and the Darcy-Weisbach equation calculator for pipe flow analysis. Buoyancy and Archimedes' principle calculators cover floating and submerged objects, while hydrostatic pressure, hydraulic pressure, and manometer calculators measure fluid pressure.

This section also includes pump horsepower, orifice flow, flow rate, and friction loss calculators for practical fluid system design, plus specific gravity, surface tension, water density, and water viscosity calculators, and Froude number, Weber number, and Knudsen number calculators for dimensionless flow analysis.

Kinematics Calculators cover motion without worrying about the forces that cause it. Calculate velocity, acceleration, and displacement with the SUVAT calculator, or work through projectile motion, projectile range, and maximum height for objects launched at an angle. The free fall calculator and free fall with air resistance calculator model falling objects, while terminal velocity and g-force calculators cover velocity limits and acceleration forces.

This section also includes muzzle velocity, arrow speed, and ballistic coefficient calculators for ballistics, plus stopping distance, quarter mile, trajectory, and time of flight calculators for vehicles and projectiles in motion.

Machines & Mechanisms Calculators cover the mechanical advantage and sizing math behind simple and complex machines. Calculate mechanical advantage with the lever calculator, pulley calculator, and fulcrum calculator, or size a gear ratio with the gear ratio, gear ratio RPM, and gear ratio speed calculators. Engine and drivetrain tools include engine displacement, piston force, piston speed, and BMEP calculators, while spring, spring rate, and torsion spring calculators cover mechanical energy storage.

This section also includes a belt length calculator, bolt torque calculator, shaft size calculator, linear actuator force calculator, prop pitch calculator, drone motor calculator, and wing loading calculator for a wide range of mechanical design problems.

Materials & Continuum Mechanics Calculators cover how materials deform and fail under load. Calculate stress and strain directly, or use Young's modulus calculator and shear modulus calculator to relate stress to deformation. Beam analysis is covered by beam deflection, beam load, and bending stress calculators, while buckling, factor of safety, and stress concentration factor calculators assess structural failure risk.

This section also includes hardness testing tools like Brinell hardness number, Rockwell hardness conversion, and Vickers hardness number calculators, plus Poisson's ratio, bulk modulus, Von Mises stress, Mohr's circle, and principal stress calculators for advanced stress analysis, and density calculators for spheres, cubes, and cylinders of different materials.

Nuclear Physics Calculators cover radioactive decay and nuclear reaction energetics. Calculate radioactive decay and activity (Becquerel/Curie) for a given isotope, or use the Carbon-14 dating calculator to estimate the age of organic material. The mass defect calculator and nuclear binding energy calculator quantify the energy holding a nucleus together, while alpha decay energy and neutron flux calculators cover specific nuclear reactions.

This section also includes a radiation dose equivalent calculator, inverse square law calculator (radiation), and nuclear cross section calculator for radiation safety and reactor physics.

Optics & Light Calculators cover how light behaves through lenses, mirrors, and different media. Calculate focal length and use the thin lens equation calculator and lens maker equation calculator to design optical systems, or apply Snell's law calculator and critical angle calculator for refraction problems. The mirror equation calculator and prism calculator cover reflection and dispersion, while diffraction grating and Bragg's law calculators handle wave optics.

This section also includes laser-specific tools like laser beam divergence, laser spot size, laser pulse, and laser brightness calculators, plus telescope magnification, telescope field of view, and binoculars range calculators, and a blackbody radiation calculator, Malus law calculator, and index of refraction calculator for broader optics coursework.

Quantum Mechanics Calculators cover the equations that describe particles at the smallest scales. Calculate the de Broglie wavelength of a particle or photon energy from wavelength, or use the Heisenberg's uncertainty principle calculator to find the limits of simultaneous measurement. The Bohr model calculator and hydrogen atom energy levels calculator model atomic structure, while the Schrödinger equation solver and particle in a box calculator solve for quantum wave functions.

This section also includes a Compton scattering calculator, Compton wavelength calculator, photoelectric effect calculator, tunneling probability calculator, and Rydberg equation calculator for other core quantum mechanics topics.

Relativity Calculators cover how space, time, and mass behave at speeds approaching the speed of light. Calculate time dilation and length contraction using the Lorentz factor calculator, or work out relativistic momentum and mass-energy equivalence with E=mc². The velocity addition calculator combines relativistic velocities correctly, while the gravitational time dilation calculator covers time dilation from gravity rather than speed.

This section also includes classic relativity thought experiments like the barn-pole paradox calculator and bug-rivet paradox calculator, plus an electron speed calculator for finding a particle's velocity from its kinetic energy.

Rotational & Periodic Motion Calculators cover spinning, oscillating, and cyclic motion. Calculate angular velocity, angular momentum, and centripetal force for circular motion, or use the moment of inertia calculator and torque calculator for rotational dynamics. Simple harmonic motion and simple pendulum calculators cover oscillating systems, while natural frequency and damping ratio calculators describe how a system responds to disturbance.

This section also includes a centrifugal force calculator, Coriolis effect calculator, flywheel energy storage calculator, polar moment of inertia calculator, and rotational kinetic energy calculator, plus a speeds and feeds calculator for machining applications.

Statics & Equilibrium Calculators cover forces on objects that aren't accelerating. Calculate center of mass or moment of force to analyze balance and torque, or use the couple and torque calculator for rotational equilibrium. The pressure calculator and pounds per square inch calculator handle force distributed over area, while the weight on other planets calculator and age on other planets calculator apply gravity and orbital period to different celestial bodies.

Thermodynamics Calculators cover heat, temperature, and energy transfer. Apply the ideal gas law calculator or combined gas law calculator to relate pressure, volume, and temperature, or use Boyle's law, Charles' law, and Gay-Lussac's law calculators for specific gas relationships. The Carnot efficiency calculator finds the theoretical maximum efficiency of a heat engine, while enthalpy, Gibbs free energy, and entropy-related calculators cover thermodynamic potentials.

This section also includes heat transfer tools like thermal conductivity, thermal resistance, heat transfer coefficient, and Newton's law of cooling calculators, plus specific heat, latent heat, sensible heat, and heat capacity calculators for phase changes and temperature calculations, and the Stefan-Boltzmann law and Wien's law calculators for thermal radiation.